Some considerations when selecting power semiconductor modules are simple manipulability and assembly. Modern module housing designs use, for example, special press-fit technology to connect modules both to a printed circuit board and to a heat sink, for example in a single production step. Only a single screw, for example, is required for such connections. Such press-fit connections therefore provide a high-quality alternative to known soldered connections and therefore meet the requirements of modern power converter designs in a power range up to 55 kW. Such power semiconductor modules can be used in a wide variety of universal drives, variable-frequency drives, uninterruptible power supplies (UPS), inductive heating and welding systems as well as in wind power installations, solar installations and air-conditioning systems.
Module housings suitable for such press-fit technology have specially shaped, deformable press contact elements (“press-fit” pins) which are pressed into corresponding contact holes in a printed circuit board when assembling the module. The press-fit force is generated by tightening a single screw. The press contact elements in the contact holes in the printed circuit board are plastically deformed by tightening the screw. A gas-tight contact zone which is very robust with respect to environmental influences is produced.
Alternatively, modules can be pressed into printed circuit boards and fastened to the heat sink independently of the press-fit operation using screws or other means (before or after they are pressed into the printed circuit board). Power semiconductor modules have hitherto only been pressed into printed circuit boards as a whole. Other connection elements, for example low-inductance strip conductor pairs (also so-called “busbars”) are contact-connected in another manner (for example screwed).
However, before assembling the printed circuit board and module, it must be ensured that the press contact elements are not deformed. Otherwise problems may arise during assembly. Furthermore, the press contact elements on the module housing are connection elements which are geometrically relatively complicated to produce. The press-fit contacts often cannot be released and reconnected without a relatively large amount of effort on account of the remaining deformation of the contact elements on the module.